def calculate_chi_square(self, term, classs): N = Tokens.get_count_email() a = Tokens.get_count_term_on_class(term, classs) b = Tokens.get_count_term_not_on_class(term, classs) c = Tokens.get_count_not_term_on_class(term, classs) d = Tokens.get_count_not_term_not_on_class(term, classs) nom = (N * (A * D - B * C) * (A * D - B * C)) denom = ((A + C) * (B + D) * (A + B) * (C + D)) chi_square = nom / denom return chi_square
